Impact of arsenic in foodstuffs on the people living in the arsenic-affected areas of West Bengal, India

Abstract

Although the accumulation of arsenic (As) in human blood is linked with some diseases and with occupational exposure, there are few reports on speciation of As in blood. On the basis of our earlier article,^{[ 1 ]} elevated level of arsenicals in human urine and blood were found in the ex-exposed population via As-containing drinking water. The aim of the present study was to get an insight on impact of As in foodstuffs on the people living in the As-affected areas. Moreover, speciation of arsenicals in urine, and water-samples found in arsenobetaine (AsB). Since sampling population (n = 25) was not taking any seafood, As in foodstuffs was thought to be the prime source for this discrepancy. So, speciation of methanol extract of freeze-dried red blood cells (RBCs) and foodstuffs, and trichloro acetic acid (TCA) treated plasma by high performance liquid chromatography-inductively coupled argon plasma mass spectrometer (HPLC-ICP MS) collected from the study population (n = 33) was carried out to support our hypothesis. Results showed that urine contained AsB (1.7%), arsenite (iAs^III) (14.3), arsenate (iAs^V) (4.9), monomethylarsonous acid (MMA^III) (0.64), monomethylarsonic acid (MMA^V) (13.6), dimethylarsinous acid (DMA^III) (7.7), and dimethylarsinic acid (DMA^V) (65.4). Blood contained 21.3 μ g L^{− 1} (mean) As and of which 27.3% was in plasma and 72.7% in RBCs. RBCs contained AsB (21.6%) and DMA^V (78.4) and blood plasma contained AsB (12.4%), iAs^III (25.9), MMA^V (30.3), and DMA^V (31.4). Furthermore, speciation of As in foodstuffs showed that most of them contained AsB (3.54–25.81 μ g kg^{− 1}) (25.81–312.44 μ g kg^{− 1}) along with iAs^III (9.62–194.93), iAs^V (17.63–78.33), MMA^V (9.47–73.22) and DMA^V (13.43–101.15) that supported the presence of AsB and elevated As in urine and blood samples of the present study group. Inorganic As (iAs) predominates in rice (67.17–86.62%) and in spices (40–90.35%), respectively over organic As. So, As in the food chain is a real threat to human health.

Keywords:

• Arsenic in human blood
• foodstuffs and urine
• speciated arsenicals in freeze-dried RBCs
• plasma
• urine and foodstuffs
• food chain
• ICP MS

Acknowledgments

Dr. Badal Kumar Mandal acknowledges the help of JSPS, Japan for the financial support. This study was supported by Grants-in-Aid of Ministry of Education, Science, Sports and Culture (Nos. 12000236 and 12470509). Also, the authors highly appreciate the help and extended collaboration of SOES, JU-Calcutta during the collection of the samples from the As-affected areas of West Bengal, India.

Notes

^a t₁As ∼ Concentration of total As after speciation;

^b tAs ∼ Concentration of total As after H₂O₂/HNO₃digestion; SD ∼ standard deviation.

¹n = total number of samples;

²SD = Standard Deviation;

³As means ‘sum of all arsenical concentrations after speciation’;

⁴Polished rice;

⁵Non-polished rice.